When attaching a user equipment to a communication system based on GSM (Global system for mobile communication), for instance GPRS (general packet radio service; see for instance European standard (telecommunications series) EN 301 113) or UMTS (universal mobile telecommunications system; see for instance ETSI standard ES 201 385) standard, the user equipment usually sends an attachment request and Packet Data Protocol context activation request to a support node and will then be attached to the access network, e.g. GSM PLMN (public land mobile network) or UMTS PLMN, and connected to an external network (e.g. Internet). The access network provides the connection for instance by attributing a bearer channel. In a packet switched telecommunication system such as GPRS or UMTS, the data including user traffic data and control (signalling) data are normally sent from the user equipment to a serving support node which may send this data to a second support node, such as a gateway support node, for transmitting the communication to a receiving party which may be located in an an external network.
In addition, tunneling mechanisms are well-known especially over IP. An example of such tunneling mechanism is GTP (GPRS Tunneling protocol which in its version 1 identify a tunnel with a destination address (tunnel endpoint address, Ipv4 or Ipv6 for GTP) indicating the node of processing card handling the tunnel and a Tunnel End Point Identifier (TEID) indentifying the tunnel within this entity. Every entity sends packet with the TEID allocated by the other tunnel end and receive packets with the TEID it has itself allocated.
Usually, there is the overall tendency to reduce the traffic load in communication networks. However, different situations have to be taken into account such as a request for transmitting and receiving a communication to and from another communication network, or a request for Lawful Interception (monitoring) of a party or user equipment by a law enforcement agency authorised to monitor this party or user equipment.